Writing fiction has many aspects, and the importance of dialog writing cannot be over-estimated. Realistic dialog pulls you right in to a story or dialog, whereas stilted stuff gets rejected after a few lines.
You listen to people talk all the time, right? So it should be easy to write dialog, right?
Unfortunately, the answer is NO!
I am not sure how good my own dialog writing is, and so I have been looking up some resources. The best I found so far was this book: Writing Dialogue, by Tom Chiarella. This guy gives you some really neat tips.